Conductive Two-Dimensional Titanium Carbide ‘Clay’ with High Volumetric Capacitance

Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors in particular, pseudocapacitors. The best volumetric capacitances of carbonbased electrodes are around 300 farads per cubic centimetre. MXenes have proved to be promising candidates for electrodes in lithium-ion batteries and super-capacitors, exhibiting volumetric capacitances. The activated carbon electrodes were prepared by mechanical processing of a pre-mixed slurry, containing ethanol, YP-50 activated carbon powder, and polytetrafluoroethynene binder. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic cycling were performed using a VMP3 potentiostat. Transmission electron microscopy of the MXene flakes was performed on a JEM-2100 using an accelerating voltage of 200 kV.